5 ideas
| 10121 | Contradiction is not a sign of falsity, nor lack of contradiction a sign of truth [Pascal] |
| Full Idea: Contradiction is not a sign of falsity, nor the lack of contradiction a sign of truth. | |
| From: Blaise Pascal (works [1660]), quoted by A.George / D.J.Velleman - Philosophies of Mathematics Ch.6 | |
| A reaction: [Quoted in Auden and Kronenberger's Book of Aphorisms] Presumably we would now say that contradiction is a purely formal, syntactic notion, and not a semantic one. If you hit a contradiction, something has certainly gone wrong. |
| 14288 | 'If A,B' affirms that A⊃B, and also that this wouldn't change if A were certain [Jackson, by Edgington] |
| Full Idea: According to Jackson, in asserting 'If A,B' the speaker expresses his belief that A⊃B, and also indicates that this belief is 'robust' with respect to the antecedent A - the speaker would not abandon A⊃B if he were to learn that A. | |
| From: report of Frank Jackson (On Assertion and Indicative Conditionals [1979]) by Dorothy Edgington - Conditionals (Stanf) 4.2 | |
| A reaction: The point is that you must not believe A⊃B solely on the dubious grounds of ¬A. This is 'to ensure an assertable conditional is fit for modus ponens' - that is, that you really will affirm B when you learn that A is true. Nice idea. |
| 13769 | Conditionals are truth-functional, but should only be asserted when they are confident [Jackson, by Edgington] |
| Full Idea: Jackson holds that conditionals are truth-functional, but are governed by rules of assertability, rather like 'but' compared to 'and'. The belief must be 'robust' - the speaker would not abandon his belief that A⊃B if he were to learn that A. | |
| From: report of Frank Jackson (On Assertion and Indicative Conditionals [1979]) by Dorothy Edgington - Conditionals 17.3.2 | |
| A reaction: This seems to spell out more precisely the pragmatic approach to conditionals pioneered by Grice, in Idea 13767. The idea is make conditionals 'fit for modus ponens'. They mustn't just be based on a belief that ¬A. |
| 1474 | Moral evil may be acceptable to God because it allows free will (even though we don't see why this is necessary) [Plantinga, by PG] |
| Full Idea: Moral evil may be acceptable to a benevolent God because it is the only way to allow genuine free will, which may have a supreme value in creation (even if we are unsure what it is). | |
| From: report of Alvin Plantinga (Free Will Defence [1965], Pref.) by PG - Db (ideas) |
| 1475 | It is logically possible that natural evil like earthquakes is caused by Satan [Plantinga, by PG] |
| Full Idea: Physical evil (e.g. earthquakes) may be attributable to a fallen angel (Satan), who is the enemy of God, and this is enough to retain the idea that God is omnipotent and benevolent, and yet evil exists. | |
| From: report of Alvin Plantinga (Free Will Defence [1965], III) by PG - Db (ideas) |